Nowadays, a portable arithmetic processing device such as a so-called notebook personal computer (PC) is capable of storing multiple items of data in a memory of a hard disk etc. Management of the data stored in the hard disk etc such as this is put into hands of a purchaser and a user. Supposing a case that this arithmetic processing device gets separated from hands of the purchaser or the user, the purchaser or the user sets a scheme that apiece of information such as a password is requested of another person (third party) in order to prevent this another person from easily accessing the data when starting up OS (Operating System) and BIOS (Basic Input Output System).
Even when security of the data in the memory can be enhanced by the information such as the password, however, the data can be accessed by stealing the information such as the password. Therefore, the data security can not be ensured perfectly even by enhancing the security of the data in the memory through the password.
FIG. 6 is a flowchart showing a simplified illustration of a conventional method of remotely processing the data in order to ensure the data security.
To start with, the arithmetic processing device receives information to delete the data from a user's mobile terminal device via a telephone communication network (step S100). The arithmetic processing device is thereby automatically booted (step S102).
Next, it is determined whether or not a condition for erasing the data is fulfilled, e.g., whether or not there is information indicating that the arithmetic processing device is stolen, etc (step S104). If a result of the determination is affirmative (YES), a data erasing process is carried out (step S106). Upon finishing the data erasing process, the arithmetic processing device is shut down (shutdown) (step S108). Note that whereas if the result of the determination in step S104 is negative (NO), the arithmetic processing device is promptly shut down (step S108). Thus, the data erasing process is executed.
Further, the following Patent document 1 describes a system given below for ensuring the data security of the notebook PC.
To be specific, a center device at a mobile terminal monitor center is always notified of a present location of the notebook PC possessed by the user and a present location of the mobile terminal device that is carried by the user at all times via the network. When detecting that a distance calculated by the center device between the mobile terminal device and the notebook PC becomes equal to or larger than a preset fixed distance, an operator immediately notifies the mobile terminal device of alarm information saying this purport from a telephone for a call center. Further, the user issues an instruction to delete the data on the notebook PC separated at a fixed or longer distance, and the telephone for the call center accepts this instruction, in which case the center device transmits a delete command signal to the notebook PC via the network, thereby deleting the data on the notebook PC.
With this operation, it is considered that a theft and a loss of the notebook PC possessed by the user can be monitored, and the data can be prevented from leaking out and flowing out when stolen and lost.
In the system of the Patent document 1, an instruction signal is transmitted for deleting the data on the notebook PC. The perfect deletion of the data on the notebook PC, however, requires a given period of processing time and a sufficient battery quantity. Therefore, even when the notebook PC receives the instruction signal and starts processing, there is a case in which the data is not completely erased due to restrictions on the processing time and on the battery quantity with the result that the data is still partially left. This leads to a problem that there still remains a possibility of leaking and flowing the data out.    [Patent document 1] Japanese Patent Application Laid-Open Publication No. 2007-36672